Issue 33, 2018

Implications of cation-disordered grain boundaries on the electrochemical performance of the LiNi0.5Co0.2Mn0.3O2 cathode material for lithium ion batteries

Abstract

Although lithium-mixed transition metal oxides (LiTM) have promising properties suitable for practical applications, unavoidable cation disorder in their structure during their synthesis or their operation leads to complex effects on their electrochemical performance. The microscopic mechanism of the cation disorder remains elusive owing to the lack of information on the atomic structures with specific chemical identities. In this study, the Li-content-dependent cation disorder phenomenon near the grain boundary of LiNi0.5Co0.2Mn0.3O2 particles is uncovered using atom-resolved chemical and valence mapping techniques. LiTM with 1% excess Li (LiTM101) shows outstanding electrical conductivity at the grain boundary, whereas no enhancement in the electrical conductivity is manifested in LiTM with 7% excess Li. Remarkably, this superior property of LiTM101 is coupled to the combined cation disorder of Ni and Co in the Li layer with their increased valences, while the Mn ions in both samples are not labile to migrate. This work highlights the hitherto hidden role of highly oxidized Co ions in the Li layer as a key agent for enhancing the electrochemical performance, together with Ni ions acting as pillars to stabilize the layered structure, thus providing a new insight for engineering stable and durable cathode materials with high performance.

Graphical abstract: Implications of cation-disordered grain boundaries on the electrochemical performance of the LiNi0.5Co0.2Mn0.3O2 cathode material for lithium ion batteries

Supplementary files

Article information

Article type
Paper
Submitted
21 мај 2018
Accepted
21 јул. 2018
First published
23 јул. 2018

J. Mater. Chem. A, 2018,6, 16111-16120

Implications of cation-disordered grain boundaries on the electrochemical performance of the LiNi0.5Co0.2Mn0.3O2 cathode material for lithium ion batteries

J. Shim, J. Im, H. Kang, N. Cho, Y. Kim and S. Lee, J. Mater. Chem. A, 2018, 6, 16111 DOI: 10.1039/C8TA04731F

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements